Box port issue

Hey guys, I got measured on a termlab and was upset with my results. I hit a 139.5 with my single hdc3 15 on 1700 watts.

I thought about how I could make my setup louder and my mind crossed my subwoofer box. I thought it was tuned to 35hz when I built it but it turns out it peaks at 42hz. When I was building the slot port, I didn't make sure the ports were 90 degrees.

Basically, I think it's tuned into the 40s now because the port gets more and more narrow into the box. Is this harming my spl?
(box is 3.75 cubic ft on my HDC3)

You were the guy with subi outback right?

Well first off what you tune your box at, isn't what its gonna peak at from my understand.. If you wanna put up numbers I would get a any sub (even your aq if you want too) put it in a sealed enclosure and run some freq sweeps to find your resonant freq. Then ( if you want to build another enclosure) tune it so your your box peaks where your resonant freq is. Just my two cents

Also and if you do build a new box for it, sub up port back will get you louder..genreal rule of thumb with hatch backs, wagons and suv's..

What you peak at isn't going to change with your box's tuning, as stated. If you want to get louder I suggest building a more precise box, 35 hz is a fine tune. I wouldn't go any higher than 37 for daily though. When you build it make sure all your edges are flush with the other board it's being mounted to and have the corners in your port be 45* to smooth the air flow.

If you start to decide on a new box hit me up cause I'm getting bass box pro from a team member.. It does all kind of shit when it comes to enclosure to make sure your enclosure doesn't have any flaws

Just got the new box built
71 Cubic ft. of Port. 4.95^3 @35.5hz. Sub up port back in my wagon!
Giving my HDC3 about 1500 watts so hopefully the box isn't to big..
EDIT- Nice little 45 in the port also

That seems about right with the power your running.. Is the 4.95 cubes before or after displacement?

After displacements.. That's why I'm a bit worried:/

Just be careful on the gain, I would start low and figure out the sweet spot from there. Larger box = more efficient = less power needed.

Yeah, that's what I was thinking.. I oscoped my gain yesterday and in the small box the AQ got warm and even smelled a little. Maybe I shouldn't have used a -5db tone. Oh well, I just turn it down a bit when I put it in the new box..
What should I set my ssf to, about 25-30hz?

id say 30hz would be good.. ive always been told to set your subsonic just under the tuning of your box ..